My 2003 3.0D has Bilstein as OEM (the stickers are still on them). My Alfa Romeo 147 has aftermarket Bilsteins as the OEM shocks are crap. They did lift the car a little bit, the rears actually came with nylon strapping to stop the shafts from pushing past the ends of the packaging.

Vinuneuro, i agree with most of your comments but surely different drivers want different ride/handling characteristics and that BMW (indeed any other car maker) tries to give the best compromise to the widest possible market. Why would BMW offer a sport suspension option if they got it right the first time? I'm sure the folks at Bilstein might put a bit more of an effort than you allude to. When the OEM shocks need replacing, I'd definitely consider upgrading to 'aftermarket' Bilsteins.